dbcve.org
Windows 10 1507Operating system · Microsoft

CVE-2025-55687

HIGH · 7.0 CVSS v3.1 Published 2025-10-14
Fix available
A fix is available. Upgrade to 10.0.10240.21161 / 10.0.14393.8519 or later.
See remediation →
72/100
Remediation priority · Elevated
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Resilient File System (ReFS) allows an unauthorized attacker to elevate privileges locally.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A race condition vulnerability exists in Windows Resilient File System (ReFS) where improper synchronization of shared resources during concurrent operations allows a local attacker to exploit the timing window and elevate privileges to higher permission levels.

MitigationApply Microsoft security updates for CVE-2025-55687 when released. Prioritize patching systems using ReFS and limit local unprivileged access to affected systems until the patch is applied.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Windows 10 1507Operating system
Affected:< 10.0.10240.21161
Windows 10 1607Operating system
Affected:< 10.0.14393.8519
Windows 10 1809Operating system
Affected:< 10.0.17763.7919
Windows 10 21h2Operating system
Affected:< 10.0.19044.6456
Windows 10 22h2Operating system
Affected:< 10.0.19045.6456
Windows 11 22h2Operating system
Affected:< 10.0.22621.6060
Windows 11 23h2Operating system
Affected:< 10.0.22631.6060
Windows 11 24h2Operating system
Affected:< 10.0.26100.6899

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
High
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check Windows build number
    Run 'winver' or 'systeminfo | findstr /B /C:"OS Version"' to get the exact build number. Alternatively, run 'ver' at command prompt.
    Affected if The displayed build number falls below any of these thresholds: 10240.21161 (Win10 1507), 14393.8519 (Win10 1607), 17763.7919 (Win10 1809), 19044.6456 (Win10 21h2/22h2), 22621.6060 (Win11 22h2), 22631.6060 (Win11 23h2), or 26100.6899 (Win11 24h2).
  2. Identify ReFS volumes on the system
    Open an elevated command prompt and run 'fsutil fsinfo volumeinfo C:' (repeat for each drive letter). Look for 'File System Name : ReFS' in the output for each volume.
    Affected if Any volume on the system shows ReFS as the file system (File System Name : ReFS). If no volumes use ReFS, the system is not vulnerable regardless of Windows version.
  3. Confirm ReFS.sys driver status
    Run 'sc query refs' or check 'C:\Windows\System32\drivers\refs.sys' exists. ReFS support may also be listed in Windows Features or via 'dism /online /get-features'.
    Affected if ReFS driver is present and the ReFS file system is available on the system.

The system is affected if it runs an unpatched Windows version within the affected build ranges AND has at least one volume formatted with ReFS; systems without ReFS volumes are not vulnerable to this specific flaw.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 10.0.10240.21161 / 10.0.14393.8519 / 10.0.17763.7919 or later
Fixed in 10.0.10240.2116110.0.14393.851910.0.17763.7919
Interim mitigation

Apply Microsoft security updates for CVE-2025-55687 when released. Prioritize patching systems using ReFS and limit local unprivileged access to affected systems until the patch is applied.

Recommended fix High confidence

Windows 10 1507: 10.0.10240.21161 | Windows 10 1607: 10.0.14393.8519 | Windows 10 1809: 10.0.17763.7919 | Windows 10 21h2: 10.0.19044.6456 | Windows 10 22h2: 10.0.19045.6456 | Windows 11 22h2: 10.0.22621.6060 | Windows 11 23h2: 10.0.22631.6060 | Windows 11 24h2: 10.0.26100.6899

  1. 1. Identify the current Windows version and build number by running 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"'
  2. 2. Navigate to Windows Update by opening Settings > Update & Security > Windows Update
  3. 3. Click 'Check for updates' to download and install the latest security updates
  4. 4. For enterprise environments, deploy the relevant security update from Microsoft Update Catalog or via WSUS
  5. 5. After installation, restart the system when prompted
  6. 6. Verify the build number matches or exceeds the fixed version for your Windows release
Caveat Standard Windows security update; no breaking changes expected for this patch

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Windows 10 1507 Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-55687 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data